Thorough cleaning of all surfaces to remove so-called “chicken juice” is essential to prevent the build-up of biofilms, which then help campylobacter survive.
New research from the Institute of Food Research has shown that campylobacter’s persistence is boosted by the presence of this exudate from chicken carcasses in poultry processing sites and kitchens.
Researchers, led by PhD student Helen Brown, collected the liquids produced from defrosting chickens, and found that this helped campylobacter attach to surfaces such as glass, polystyrene and stainless steel, and subsequently form biofilms.
Biofilms are specialised structures that protect bacteria from threats from the environment.
“We have discovered that this increase in biofilm formation was due to chicken juice coating the surfaces we used with a protein-rich film,” said Ms Brown. “This film then makes it much easier for the campylobacter bacteria to attach to the surface, and it provides them with an additional rich food source.”
Campylobacter are not particularly hardy bacteria, so one area of research has been to understand exactly how they manage to survive outside of their usual habitat, the intestinal tract of poultry.
They are sensitive to oxygen, but during biofilm formation the bacteria protect themselves with a layer of slime. This also makes them more resistant to antimicrobials and disinfection treatments.
The researchers suggest that this understanding will help efforts to reduce the high percentage of chickens that reach consumers contaminated with the bacteria.
Although thorough cooking kills off the bacteria, around 500,000 people suffer from campylobacter food poisoning each year in the UK. Reducing this number, and the amount of infected chicken on supermarket shelves, is now the number one priority of the Food Standards Agency.
“This study highlights the importance of thorough cleaning of food preparation surfaces to limit the potential of bacteria to form biofilms,” said Ms Brown.
The research was funded by the Biotechnology and Biological Sciences Research Council and Campden BRI.